This invention relates to a door construction and more particularly to a door construction which is exposed to high temperatures.
The invention is particularly applicable to use on a coke oven leveler door and will be described with particular reference thereto; however, it will be appreciated by those skilled in the art that the invention has broader applications and may be used in other environments where a door which is exposed to high temperatures must resist or be adapted to heat induced warpage which would otherwise prevent the door from properly sealing around a door frame.
Coke oven is a term of art employed for the large ovens which are used to produce coke and coke by-products from coal. While there are a number of types and styles of coke ovens, they typically have a substantial vertical height and depth in relation to the width and, in some respects, resemble a very large closet. In many instances, the heighth of these ovens is well over 10 feet and virtually the entire front face of the oven may be selectively opened and closed by means of a coke oven door. Normally, a plurality of the individual ovens are located in a side by side relationship to form what is commonly termed an oven battery in order that a high volume of coke and coke by-products may be made at one location.
In the type of oven described above, charging of the oven prior to the coking operation is done from the top thereof and the coke oven door itself includes a leveler or chuck hole opening adjacent the uppermost vertical portion thereof. A leveler door is disposed adjacent the leveler opening and is selectively movable between opened and closed positions for allowing access to the inside of the oven. This leveler opening finds its principal use in receiving a leveler bar which is reciprocated or raked across the peaked coal piles charged into the furnace in order to level them prior to beginning an actual coking operation.
In prior coke ovens, the coke oven doors and leveling doors have been constructed from cast iron since it was thought to be the best means in which to avoid undesired door warpage during coking operations. Warpage is a significant problem due to the high temperatures, e.g., 2000.degree. F and above, acting on the inside faces of the doors during a coking operation. When warpage occurs, the original close fitting or sealing relationship between the coke oven and leveler doors is distributed so that there is heat and pollution loss from the oven as well as air admission into the oven. Such circumstances are undesirable from both environmental and overall operational points of view. While prior doors have variously utilized special sealing structures, such structures have not eliminated the sealing problems when warpage occurs. The primary problem with the prior cast iron oven and leveler doors has been diagnosed as a failure of the doors to warp evenly with each other when they are subjected to the elevated temperatures of a coking operation. This difference in warpage may be attributed to the significant difference in door surface areas as well as the fact that the entire leveler door, because of its location in the oven door adjacent the uppermost portion of the oven itself, is subjected to the highest temperature developed in the oven. Thus, the two doors will warp in varying degrees so that the outer edges of the leveler door will not closely mate with the leveler door opening.
The subject invention is directed toward an improved construction for a coke oven leveler door which overcomes the above discussed problems and provides an improved leveler door structure which is simple to manufacture, readily adapted to use on virtually all types of leveler doors used on different types and styles of coke ovens, and provides a structure which facilitates continuous sealing around the periphery of the leveler door during coking operations.